Miniature electronic discharge tube with ribbon-shaped beam



March 27, 1956 H GRQENDIJK ET AL 234,063

MINIATURE ELECTRONIC DISCHARGE TUBE WITH RIBBON-SHAPED BEAM Filed May :25, 1952 2 Sheets-Sheet l jsren AGE/VT March 27, 1956 GROENDIJK ET AL 2,740,063

MINIATURE ELECTRONIC DISCHARGE TUBE WITH RIBBON-SHAPED BEAM Filed May 25, 1952 2 Sheets-Sheet 2 I c J6 1m I I 1 I United States Patent O MINIATURE ELECTRONIC DISCHARGE TUBE WITH RIBBON-SHAPED BEAM Hendrik Groendijk, Klaas Rodenhuis, and Jacobus Victor Casper Marie Bruijsten, Eindhoven, Netherlands, assignors to Hartford National Bank and Trust Com pany, Hartford, Conn, as trustee Application May 23, 1952, Serial No. 289,566

Claims priority, application Netherlands February 27, 1952 3 Claims. (Cl. 313-82) The present invention relates to miniature electronic discharge tubes wherein a ribbon-shaped electron beam is produced.

More particularly an electron tube of the above mentioned type is described wherein the beam flows along the longitudinal axis of the tube, one pair of deflection plates being provided for deflecting the beam to and fro in a direction perpendicular to the tube axis.

A purpose of the present invention is to provide a very rigid tube construction of small dimensions, notwithstanding the use of a deflected electron beam.

Other advantages will become best understood by reference to the following description taken in connection with the accompanying drawing in which:

Fig. 1 shows a sectional view of the tube along the line C--D of Fig. 3.

Fig. 2 shows a side view of the system of Fig. 1.

Fig. 3 is a cross-section over A--B of Fig. 1,

Fig. 4 is a section of a simplified construction of a tube according to the invention.

In Figs. 1, 2 and 3, 1 designates the bulb of the tube, which is closed at the bottom by a bottom piece 2, wherein contact pins 3 are arranged. The bulb has a diameter of less than 25 mm. and a length of less than 60 mm.

In the bulb 1 an electrode system is arranged comprising an elongated cathode 4 with rectangular cross-section. The cathode is indirectly heated and the terminals 5 and 6 of the heater are connected to U-shaped members '7 and 8 to which the connector wires to the corresponding contact pins 3 are attached.

The upper side of the cathode is covered with electron emitting material. The electrons are forced into a ribbonshaped beam by beam forming and control electrodes consisting of plate-shaped members 9 and 10, each arranged at an angle of 45 with the plane of the emitting surface.

In front of the cathode, there are additional control electrodes for the beam including an accelerating electrode 11 having a rectangular slit, and a second slitted electrode 12, which forms an electrostatic lens with electrode 11.

The beam can be deflected by the deflection electrodes 13 and 14, to fall on another control electrode, the slitted accelerating and screening electrode 15 or, in the centre position through the slit of this screen, on the anode 16. Between anode 16 and screen 15 may be arranged a suppressor grid 17, consisting of two supporting rods 18 on which grid wires are fastened. These wires preferably lie in a curved plane, in order to help focus the beam into the anode 16. The anode 16 is funnel-shaped in order to suppress secondary electrons.

The electrodes are firmly supported by two mica plates 1? of rectangular shape, which are firmly held by two U-shaped or channel-like support members 20 of metal, which members are connected to the slitted electrodes 12 and 15. The supply lead 21 to the grid 17 is arranged 2,740,063 Patented. Mar. 27, 1956 outside a support member 20 and connected to the cathode and a contact pin 3.

The support members 20 hold the mica members 19 by means of lips 22. The electrodes are mounted be tween these mica members 19 by means of lips 23, which are forced into triangular openings 24. As the base of these triangular openings is smaller than the breadth of the lips, the lips cut into the mica and thus are firmly held, so that no movement of the electrode is possible. The whole system is additionally supported against the tube wall 1 by a mica disc 25, which is clamped in the bulb 1. A getter 26 is attached to a U-shaped support member 19.

The mica members 19 are provided with triangular openings 27 in order to avoid disturbance of the deflection by charges which may collect on the mica surface.

A simplified construction is shown in Fig. 4, wherein the electrode system consists of a cathode 28, beaming control electrode 29, accelerating anode 30, parallel deflection plates 31 and 32, second acceleraing and screening electrode 33 and a substantially funnel-shaped anode 34. These electrodes are, according to the invention, supported between rectangular mica members 35 and U- shaped metal support members 36 in the same way as in Figs. 1 and 2. A ruggidising insulating mica member 37 prevents displacement of the system in a direction perpendicular to the longitudinal axis of the tube.

While we have thus described our invention with specific examples and embodiments thereof, other modifications are readily apparent to those skilled in the art Without departing from the spirit and the scope of the invention as defined in the appended claims.

What we claim is:

1. An electron discharge tube comprising a tubular elongated envelope; an electrode system disposed Within said envelope, said electrode system comprising means for producing a ribbon-shaped electron beam in the longitudinal direction of the envelope, means for deflecting the beam in directions perpendicular to said longitudinal direction, means for collecting said beam, and at least one additional electrode for controlling the beam; and a support for said electrode system, said support comprising an elongated closed box-like member disposed within the envelope and extending in the longitudinal direction of the envelope and enclosing said electrode system, said box-like member comprising a pair of opposed flat rectangular insulating members and a pair of opposed elongated channel-like metal members each including a pair of spaced leg portions and a flat bight portion, said channel-like metal members being of substantially the same length as said insulating members and forming With the latter the elongated box-like member, each of said leg portions being secured to the adjacent portions of the insulating members, said support including a fiat insulating disc extending in a plane perpendicular to the longitudinal direction of the tube and secured to the end of the box-like member remote from the beam-producing means and in engagement with the inner surface of said envelope; the beam-producing, deflecting and collecting means of said electrode system being secured to and between said insulating members and thus within the boxlike member and insulated from the channel-like metal members, said metal members serving as lead means for said additional electrode.

2. An electron discharge tube as claimed in claim 1 wherein the opposed insulating members and the flat insulating disc are all constituted of mica.

3. An electron discharge tube as claimed in claim 1 wherein the additional control electrode includes a pair 'df slitted electmdes one-"disposed in front of and the other References Gited inthe file of this patent UNITED STATES PATENTS McNally Apr. 13, 1937 Shockley July 9, 1940 ,4. Rockwood Dec. 16, 1941 .-Pierce-..--- .-Dec. 30,1941 Linder v Mar. 17, 1942 Herold Sept. 1, 1942 Green etal. Nov. 19, 1946 Sziklai Sept. 14, 1948 Game -ZFbJ 27, 1 95 1 

